>>280192844
Furinkan notes that: "The onomatopoeia that appears around the foreigner that thanks Rinne says "ペラペラ" (perapera). This is the "sound" of fluent speaking."

And yes, the foreigners dialogue was written in English in the original manga as well. The font was different, but I guess VIZ thought the rather plain Helvetica looking font didn't suit the comic book style lettering of the rest of the localization and went with a clearly distinct font but one that also looks arguably more fitting.